Final say for overrriding NOx fumes

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ahmadbayoumi
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Final say for overrriding NOx fumes

Post by ahmadbayoumi » January 2nd, 2019, 1:37 pm

Hello Dears,

I’m intending to process a large batch of gold plated pins using nitric acid (concentrated 60% or 50/50 30% acid ) bath.

My main concern here is how to override the NOx fumes (NO and/or NO2) coming out of the reaction as a health and environmental consideration.

I have read here in this forums many discussions about using H2O2 with EG (Ethylene Glycol) directly into the acid bath to suppress or eliminate the NOx emission.

Also, I have read about using both Urea and Sulfamic acid as an alternative for the H2O2 due to cost consideration as H2O2 is much more expensive than Urea and Sulfamic acid.

Now, I need your help to provide the final say on this topic .. what is the most efficient way to suppress the NOx fumes ?!

This is in terms of suppression efficiency, cost considerations, stability and controllability.

Thanks in advance :)

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Re: Final say for overrriding NOx fumes

Post by Geo » January 2nd, 2019, 4:04 pm

The most efficient is using a reflux apparatus. Using a flask and a reflux condenser will not remove all of the NO2 but it will greatly reduce the output. It also returns some of the nitric acid back to the reaction reducing acid use.
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Re: Final say for overrriding NOx fumes

Post by archeonist » January 2nd, 2019, 5:51 pm

Why don't you use the sulfuric cell? Is it time? Or is de batch just that big? I would also consider a reflux condensor. Most of the NO2 will condense to a liquid and fall back into the solution.

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Re: Final say for overrriding NOx fumes

Post by ahmadbayoumi » January 3rd, 2019, 7:01 am

Reflux Apparatus .. Well, this is new for me but I may need to add it to my options .. thanks dears :)

Now, I have 3 alternatives

1- Reflux Apparatus
2- H2O2/EG
3- Urea/Sulfamic acid

Now, I have been told that the Reflux Apparatus is the most efficient method to suppress the NOx.

So what about scalability ?! is it (Reflux Apparatus) applicable for large setup (large barrels with many Kgs of gold plated pins) ?!

If yes, how to setup such system and scale it up ?

If No, so what about other alternatives ?

In my country, I can get 50% H2O2 with almost 1$/L and both Urea/Sulfamic acid with the same price 1$/Kg

So, I would really appreciate if we can discuss each option in terms of the following factors:
1- Scalability
2- Efficiency
3- Stability and Controllability
4- Cost
archeonist wrote:
January 2nd, 2019, 5:51 pm
Why don't you use the sulfuric cell? Is it time? Or is de batch just that big? I would also consider a reflux condensor. Most of the NO2 will condense to a liquid and fall back into the solution.
I'm using Sulfuric cells but for heavy gold plated connectors/pins .. however, for tiny and light pins, I think it's more efficient to use the Nitric (concentrated or 50/50) bath then collect gold foils then go directly for either AR or AP .. using this way is the most efficient way for my case in terms of cost (1L of 60% HNO3 = 0.25$), Scalability, and time.

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Re: Final say for overrriding NOx fumes

Post by kurtak » January 3rd, 2019, 8:13 am

ahmadbayoumi wrote:
January 3rd, 2019, 7:01 am

Now, I have 3 alternatives

1- Reflux Apparatus
2- H2O2/EG
3- Urea/Sulfamic acid ----------


So what about scalability ?! is it (Reflux Apparatus) applicable for large setup (large barrels with many Kgs of gold plated pins) ?!


So, I would really appreciate if we can discuss each option in terms of the following factors:
1- Scalability
2- Efficiency
3- Stability and Controllability
4- Cost


so what about other alternatives ?
Per the underlined - IMO (In My Opinion) - you really need to look into cyanide leaching

It will solve "all" the problems in red

Edit to add; - it will also reduce your waste by "A LOT" over that of using acid methods - plus in the end you will have the bonus of your copper/brass as a by product

Kurt

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Re: Final say for overrriding NOx fumes

Post by ahmadbayoumi » January 3rd, 2019, 10:37 am

Actually, I didn't have the chance to work with cyanide before.

May be due to the danger associated with it .. don't know 8)

So I don't know anything about the cyanide leaching process so seems it's not one of my options yet .. maybe later 8)

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Re: Final say for overrriding NOx fumes

Post by Geo » January 3rd, 2019, 2:07 pm

A reflux condenser is very easy. It is scalable. The restrictions will be reaction vessel size. There are reflux condensers that are specifically made for the purpose although distillation condensers will work as a substitute.
Another option is using a scrubber to remove the NOx before being released to the atmosphere. It is a waste as the fumes are neutralized where a reflux condenser recycles some of the acid. A scrubber can be incorporated with the reflux condenser to completely remove any remaining NOx before being released.
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Re: Final say for overrriding NOx fumes

Post by nickvc » January 3rd, 2019, 5:08 pm

While working with cyanide can be dangerous so long as you understand it’s dangers it’s one of the best tools in recovery out there, I believe if done correctly it will be the best choice for this material but it needs to run weak as over strength solutions will cause problems with co dissolving base metals, the weaker the solution the more selective it is but the more solution you have to deal with, like most processes there’s a pay off one way or the other.
Using acids should remove all the base metals and leave a rich concentrate to refine but the costs and fumes are the pay back, it all depends on what you have access to and what experience you have as to which method you choose.

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Re: Final say for overrriding NOx fumes

Post by anachronism » January 4th, 2019, 5:36 am

ahmadbayoumi wrote:
January 2nd, 2019, 1:37 pm
Hello Dears,

I’m intending to process a large batch of gold plated pins using nitric acid (concentrated 60% or 50/50 30% acid ) bath.

Hi there

Before we get ahead of ourselves can you clarify what you mean by "a large batch?"

Jon
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Re: Final say for overrriding NOx fumes

Post by g_axelsson » January 4th, 2019, 6:07 am

ahmadbayoumi wrote:
January 2nd, 2019, 1:37 pm
Also, I have read about using both Urea and Sulfamic acid as an alternative for the H2O2 due to cost consideration as H2O2 is much more expensive than Urea and Sulfamic acid.
Can you please explain how you are going to use sulfamic or urea to keep NOx fumes down? That's something I've never heard before.

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Re: Final say for overrriding NOx fumes

Post by kurtak » January 4th, 2019, 8:26 am

anachronism wrote:
January 4th, 2019, 5:36 am
ahmadbayoumi wrote:
January 2nd, 2019, 1:37 pm
Hello Dears,

I’m intending to process a large batch of gold plated pins using nitric acid (concentrated 60% or 50/50 30% acid ) bath.

Hi there

Before we get ahead of ourselves can you clarify what you mean by "a large batch?"

Jon
Agreed - before giving "proper " advice we really do need to know how much material we are dealing with
(large barrels with many Kgs of gold plated pins) ?!
How big are the barrels - how many Kg per barrel - how many barrels - is it a one time deal or do you get it in on a regular bases

Pictures of the material would helpful :!:

Kurt

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Re: Final say for overrriding NOx fumes

Post by ahmadbayoumi » January 4th, 2019, 9:08 am

g_axelsson wrote:
January 4th, 2019, 6:07 am
ahmadbayoumi wrote: ↑
January 2nd, 2019, 8:37 pm
Also, I have read about using both Urea and Sulfamic acid as an alternative for the H2O2 due to cost consideration as H2O2 is much more expensive than Urea and Sulfamic acid.

Can you please explain how you are going to use sulfamic or urea to keep NOx fumes down? That's something I've never heard before.
Actually, I got this information from one old thread http://www.goldrefiningforum.com/phpBB3 ... es#p127090
goldsilverpro also mentioned a patent that used a very low concentration of Urea and Sulfamic acid that also reduced NOx fumes and also speed up reactions, has anyone tried this method yet? This was mentioned over 2 years ago, and I figured that by now someone would have tried it.
So I though it's another method to overcome the NOx fumes but if it's not .. so simply, it's not.

I know the logic and the chemical reactions behind using H2O2 but I don''t for Sulfamic/Urea combinations and that why I'm asking if it's one of the alternatives or not and I need your hands-on experience on this topic because the emitted NOx fumes have both environmental and Health serious threats.
kurtak wrote:
January 4th, 2019, 8:26 am
Hi there

Before we get ahead of ourselves can you clarify what you mean by "a large batch?"

Jon

Agreed - before giving "proper " advice we really do need to know how much material we are dealing with
Well .. what I meant here by large batches in large barrels is 10s ok Kgs of gold plated pins extracted out from old exchanges plugs (Nortel/Alcatel) .. they are are very nice ones and I made a test for them and 1Kg of these pins will yield around 10gs of pure 24k gold (confirmed and not speculated ).

I will have 10s of kgs of these pins so I'll setup large barrels (Like the one in the below pic) to be able to accommodate this large batch ..

Now, one of the my main concerns is to find a way to suppress or eliminate the expected NOx fumes coming out of this Nitric bath process I'm intending to use for both environmental and health considerations.

I don't have pics for these plugs right now as I'm out of my home but I'll and will post them here.
barrel.jpg
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Re: Final say for overrriding NOx fumes

Post by g_axelsson » January 4th, 2019, 9:27 am

ahmadbayoumi wrote:
January 4th, 2019, 9:08 am
g_axelsson wrote:
January 4th, 2019, 6:07 am
ahmadbayoumi wrote: ↑
January 2nd, 2019, 8:37 pm
Also, I have read about using both Urea and Sulfamic acid as an alternative for the H2O2 due to cost consideration as H2O2 is much more expensive than Urea and Sulfamic acid.

Can you please explain how you are going to use sulfamic or urea to keep NOx fumes down? That's something I've never heard before.
Actually, I got this information from one old thread http://www.goldrefiningforum.com/phpBB3 ... es#p127090
goldsilverpro also mentioned a patent that used a very low concentration of Urea and Sulfamic acid that also reduced NOx fumes and also speed up reactions, has anyone tried this method yet? This was mentioned over 2 years ago, and I figured that by now someone would have tried it.
So I though it's another method to overcome the NOx fumes but if it's not .. so simply, it's not.

I know the logic and the chemical reactions behind using H2O2 but I don''t for Sulfamic/Urea combinations and that why I'm asking if it's one of the alternatives or not and I need your hands-on experience on this topic because the emitted NOx fumes have both environmental and Health serious threats.
I think the second post in that thread nailed it.
Lino1406 wrote:
November 11th, 2010, 11:41 am
Urea in the scrubber - best NO2 killer, turns it into N2.
If you use it in the working solution you'll get a mess
You need a scrubber to scrub the NOx gases coming from the barrel. The H2O2 method mixes in the peroxide with the acid to reduce the gases emitted. That will cut down on the acid you need to use to dissolve the metal, especially if you can rig up a reflux system.

It is a good thing you take care of the environment, that amount of pins dissolved in nitric acid would create a lot of NOx fumes.

Göran
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Re: Final say for overrriding NOx fumes

Post by anachronism » January 4th, 2019, 10:23 am

ahmadbayoumi wrote:
January 4th, 2019, 9:08 am


Well .. what I meant here by large batches in large barrels is 10s ok Kgs of gold plated pins extracted out from old exchanges plugs (Nortel/Alcatel) .. they are are very nice ones and I made a test for them and 1Kg of these pins will yield around 10gs of pure 24k gold (confirmed and not speculated ).

I will have 10s of kgs of these pins so I'll setup large barrels (Like the one in the below pic) to be able to accommodate this large batch ..


I don't have pics for these plugs right now as I'm out of my home but I'll and will post them here.

barrel.jpg
Do they look anything like this Nortel/Ericsson barrel of plugs or is it something different?
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Re: Final say for overrriding NOx fumes

Post by ahmadbayoumi » January 4th, 2019, 12:01 pm

ahmadbayoumi wrote:
January 4th, 2019, 9:08 am
You need a scrubber to scrub the NOx gases coming from the barrel. The H2O2 method mixes in the peroxide with the acid to reduce the gases emitted. That will cut down on the acid you need to use to dissolve the metal, especially if you can rig up a reflux system.

It is a good thing you take care of the environment, that amount of pins dissolved in nitric acid would create a lot of NOx fumes.

Göran
Would you guide me Göran how to build up my own scrubber and reflux system ?

This is after using the H2O2 to reduce the amount of emitted gases
anachronism wrote:
January 4th, 2019, 10:23 am
Do they look anything like this Nortel/Ericsson barrel of plugs or is it something different?
No they don't .. I have worked with this kind of connectors before .. and as I can remember the yield was around 3-3.5 gs of gold/kg

The pins were cut of Alcatel/Nortel cables with end plugs like the one the the below pic.
14wbz1w.jpg
Of course, it's not the same but the plugs looks like these ones.

I'll share with you the pic for the actual plugs/pins soon.
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Re: Final say for overrriding NOx fumes

Post by g_axelsson » January 4th, 2019, 12:50 pm

Scrubbers have been discussed at length on the forum so there are a lot of information here. I have never built a scrubber system so I'm far from an expert. All I have learned about scrubbers (except basic physics) I have read on the forum.

If you have a problem, just ask and I'm sure several persons will help you. But start with some studies first, here is a start with some good posts 4metals wrote.
http://goldrefiningwiki.com/mediawiki/i ... p/Scrubber
Also check the posts in the library
http://goldrefiningforum.com/phpBB3/viewforum.php?f=85
A good old search will give you plenty to read.
http://goldrefiningforum.com/phpBB3/sea ... d+scrubber

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Re: Final say for overrriding NOx fumes

Post by kurtak » January 6th, 2019, 12:32 pm

ahmadbayoumi

I posted
Per the underlined - IMO (In My Opinion) - you really need to look into cyanide leaching

It will solve "all" the problems in red

Edit to add; - it will also reduce your waste by "A LOT" over that of using acid methods - plus in the end you will have the bonus of your copper/brass as a by product
You replyed
Actually, I didn't have the chance to work with cyanide before.

May be due to the danger associated with it .. don't know

So I don't know anything about the cyanide leaching process so seems it's not one of my options yet .. maybe later
You seem to have your heart set on dissolving LARGE amounts of pins with nitric (10s of Kg) --- but - because the LARGE volume of pins you are talking about also has the problem of producing LARGE amounts of NOx which need to be dealt with - which you can certainly do --- BUT --- setting up to deal with the NOx on such a scale is in it's self going to require a "fair" size investment & work


AND it's not just the NOx you have to deal with--- you are also going to produce a HUGE amount of chemical waste (copper nitrate waste) in this process --- it takes "about" 1 gallon of 70% nitric & 1 gallon of distilled water to dissolve a Kg of pins - that is (about) 2 gallons (or about 8 liters) of waste per Kg just to dissolve the pins - then you still need to wash the copper nitrate out of the gold foils - that is going to add another gallon (plus/minus) to your waste so "about" 3 gallons (11 - 12 liters) waste per Kg --- AND - you are talking about doing this on a scale of 10's of Kg's at a time - so we are talking about producing a HUGE amount of waste - on top of a "system" to deal with the NOx on a large scale


How do you intend to deal with this HUGE scale of (copper nitrate) waste :shock: :?: :?: :?:

I am not saying that you can't do it this way - I just don't think it is the best choice in setting up for working on the scale you are talking about --- in fact I think it is about the worst choice you can make for the scale you are talking about --- of course that is just my opinion

As Nick said
While working with cyanide can be dangerous so long as you understand it’s dangers it’s one of the best tools in recovery out there, I believe if done correctly it will be the best choice for this material


Per the underlined - I agree with Nick here & I will say it again --- "you really need to look into cyanide leaching "

All the info you need to set up for cyanide leach is right here on the forum - I did a search using the simple word "cyanide" & got over 3,700 results

:arrow: http://goldrefiningforum.com/phpBB3/sea ... ds=cyanide

Look for post by Deano, 4metals, GSP, Nick & Jon in particular & you will find all the info you need to set up &/or the info you need to ask questions &/or for advice

On the scale you are talking about - cyanide leaching would be my first choice

If I could not do cyanide leaching ( because I could not get the cyanide &/or regulations prevented me from setting up to do cyanide) my next choice would be to "look into" melting the pins into anodes & then running them in a copper (refining) cell & then processing the anode slimes for the gold

For what it is worth - I spent a couple years doing some large batches of pins (30 - 50 pounds) with nitric

a little over a year ago I made a move from Wisconsin to Oregon - that resulted in shutting down my operation

The last year (before my move) I went to cyanide leaching

If I ever set up another operation - I will NEVER go back to using nitric - cyanide will be my first choice - or melting & running anodes in a copper cell as my second choice

IMO - other methods (nitric, Cu2Cl, sulfuric cell) may work fine on the hobby level - but on a "larger scale" - cyanide or electro refining cell are the better options

Kurt

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Re: Final say for overrriding NOx fumes

Post by Shark » January 6th, 2019, 1:33 pm

While I have never used cyanide, I would seriously consider that advice on large amounts of pins. I once ran 5 pounds in nitric and another 4 pounds in AP. To keep it simple, I will never do that again. At the scale I run, 3 to 5 pounds at a time, two or three times a year, I am satisfied with a sulfuric cell. Much more than that and I would be looking for a better method and cyanide seems to fit the job pretty well. I never planned to do anywhere near the things I have done in refining when I started out, but as time passed I needed a better way to save time and cost. I feel that cyanide and some other processes are dangerous, but when used properly, as with other processes we use more often, the dangers can be kept under control. Besides the amount of waste that would be produced from such large amounts it would take considerable more time. I have not tried the iodide leach but I would consider it (with more research) if I were dealing with that amount of pins. With that amount it may even be an option to look into a professional type plating/deplating setup, if you can get such amounts on a regular basis. Which ever way you go with it, keep us informed on how well your satisfied with the setup you use so us smaller time people can learn from your work as well.
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Re: Final say for overrriding NOx fumes

Post by ahmadbayoumi » January 14th, 2019, 10:41 am

Thank you very much Göran for the links about the Scrubbers :)

Will check them then will come back with questions if needed 8)

Kurt .. Thank you very much for mentioning other alternatives to Nitric leaching process :)
it's really very very annoying to see this reddish/brown fumes coming out of reaction vessels.

So, knowing other alternatives you stated (cyanide leaching/Copper refining cell) is very good specially if i'm looking to scale up the whole process by running 10s of Kgs .. so gain, thank you very much and I'll for sure start to consider these new (for me) methods.

Will check them also, then will come back with questions if needed 8)

Now, below pics are for pins i was taking about:
20190112_181811.jpg
20190112_181823.jpg
20190112_181831.jpg
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Re: Final say for overrriding NOx fumes

Post by Wizzlebiz » January 19th, 2019, 4:13 pm

ahmadbayoumi wrote:
January 2nd, 2019, 1:37 pm
Hello Dears,

I’m intending to process a large batch of gold plated pins using nitric acid (concentrated 60% or 50/50 30% acid ) bath.

My main concern here is how to override the NOx fumes (NO and/or NO2) coming out of the reaction as a health and environmental consideration.

I have read here in this forums many discussions about using H2O2 with EG (Ethylene Glycol) directly into the acid bath to suppress or eliminate the NOx emission.

Also, I have read about using both Urea and Sulfamic acid as an alternative for the H2O2 due to cost consideration as H2O2 is much more expensive than Urea and Sulfamic acid.

Now, I need your help to provide the final say on this topic .. what is the most efficient way to suppress the NOx fumes ?!

This is in terms of suppression efficiency, cost considerations, stability and controllability.

Thanks in advance :)
Screenshot_20190119-131247_Drive.jpg
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